1. Field of Invention
The present invention relates to a formable plastic product and more particularly to an improved formable tubular hollow plastic product which is relatively inexpensive and both easy to use and to form into a variety of shapes and configurations and in which the outer plastic tube is incapable of retaining a formed shape and in which a formable inner member, located within the hollow tube and which is capable of retaining a wide variety of formed shapes and spatial configurations, is used to cause the plastic tube to assume the configuration of the formable inner member.
2. Description of the Prior Art
Wire enclosed plastic articles are known in the art, for example, relatively heavy gage electrical conduit in which a copper or aluminum wire is enclosed by an insulator such as plastic. The plastic is in intimate contact with the wire and the latter normally is not moveable axially within the outer plastic sheath. Such a product, at least in the case of the heavier gage wire, can be formed into various shapes and the composite wire member tends to retain such a shape. Normally, such a product is not used as a decorative material due to the cost of the copper or aluminum wire.
Decorative products have also been fabricated of relatively small diameter copper tubing, however, this is expensive due to the cost of the copper. Further, if one forms a copper tubing into a tight bend, the tubing collapses.
Relatively small diameter and inexpensive plastic flexible tubing is known, for example, flexible polyvinyl chloride tubing, polyethylene tubing, polypropylene tubing, and a whole host of other polyolefin and other plastic materials, such as polyester, fluorinated plastics etc., to mention only a few.
Tubing of these materials is relatively inexpensive and readily available. It is also the case that these tubing materials may be easily manually shaped to various and different configurations. The difficulty in forming various configurations, however, is causing the tubular product to retain the formed configuration. If one uses a thermoset material it is possible to heat treat. the product so that it retains its configuration. To achieve this, it is normally necessary to hold the product in the desired configuration, heat it and hold it in the desired configuration while it cools. The need for a furnace or other heating device renders this impractical or too expensive for the casual user or hobbyist. Moreover, use of heat to cause a plastic product to retain its shape generally cannot be done with a thermoplastic material.
It is also known in the art to use rigid PVC tubing for various structures, see for example U.S. Pat. No. 4,730,633 of Mar. 15, 1988 in which PVC tubing is used for a structural support.
In another case, a medical device includes an outer tubular plastic sheath within which is located a metallic guide wire. The tubular plastic sheath is, in turn, surrounded by a second tubular plastic sheath, the device being an endoscope. Reference is made to U.S. Pat. No. 4,981,482 of Jan. 1, 1991. In this device, the metallic guide wire and plastic sheath are used to position the second tubular sheath in a desired location for drainage and thereafter the guide wire and plastic sheath are withdrawn from the second tubular sheath.
A wide variety of decorative and functional items may be made of plastic tubing except that some way to cause the tubing to retain its formed shape is necessary. For the hobbyist market, the product should be inexpensive and easily formed manually to any one of a variety of shapes. One formed to a desired shape, the tubular plastic product should retain that shape until reshaped. Reshaping is, of course, an advantage of any product used to form decorative items. Copper tubing, while decorative, is difficult to reshape due to the fact that it is relatively rigid tubing and the wall tends to collapse if bent sharply.
Thus, it is desirable to provide a formable plastic product which is inexpensive and which can be easily manually formed into a variety of shapes and which can retain such a shape.
Another object of this invention is to provide a tubular plastic product which is relatively inexpensive and which may be easily formed into a variety of shapes and geometrical configurations by relatively simple manual manipulation and which formed product will retain its formed shape for some period of time.
It is another object of this invention top provide a relatively inexpensive tubular plastic product composed of an outer plastic sheath inside of which is a forming member, the sheath being incapable of being formed into a predetermined shape and said forming member being spaced from the inside wall of the sheath and being capable of being easily formed to a wide variety of configurations and retaining such a configuration thus forming the sheath to essentially the same configuration.
It is also an object of this invention to provide a hollow and tubular formable plastic product which is inexpensive and which can be easily manually formed and reformed into a variety of shapes and which can retain such a shape and which tends to resist collapse if bent sharply.
The above as well as other objects are achieved in accordance with the present invention by the provision of a relatively simple and inexpensive tubular plastic sheath product which is formable into a variety of various products, as will be described in detail.
Thus, the tubular plastic product of this invention includes an outer plastic sheath which is incapable, in and of itself, of being formed into any predetermined decorative configuration and retain that configuration over time. In fact, the plastic sheath is of a type of plastic material which inherently does not retain its shape after its manufacture. Typical such materials are described.
In order to be able to form the tubular plastic sheath into a desired configuration, the interior passageway of the sheath includes a forming member, preferably a wire like member which can be manipulated by hand into any one of a variety of shapes, as will be discussed and illustrated by way of example. In a preferred form the forming member is free to move axially in the sheath and is preferably of approximately the same length as the outer sheath. In effect, the sheath forms a decorative outer cover for the forming member. The forming member also tends to prevent the tubular sheath from collapsing if the forming member and thus the sheath are bent sharply. Thus, a wide variety of materials may be used to form the outer sheath, the preferred materials being the environmentally benign plastics which are relatively inexpensive.
Accordingly, the formable plastic product of this invention preferably includes a tubular plastic sheath having a predetermined length and an internal passageway of predetermined internal diameter. The tubular sheath normally has a predetermined orientation and configuration tending to retain that orientation and configuration absent external force varying such orientation and configuration. To provide a mechanism for forming the tubular sheath into a desired configuration, a forming member is received in the passageway and extends essentially the length of said sheath. The forming member includes an outer surface portion which is unbonded to the sheath along a substantial portion of its length and spaced from intimate contact with the internal passageway of the sheath. The forming member is further characterized as being manually formable to a desired conformational shape and for retaining the desired conformational shape whereby said sheath assumes the conformational shape of the forming member as contrasted to the predetermined orientation and configuration of the tubular sheath. In the case of sharp bends, the forming member also prevents total collapse of the sheath.
The plastic tubular product of this invention may be formed into a wide variety of ornamental and creative products ranging from plant holders to desk top pen holders, and the like. The product of this invention is intended primarily for use by hobbyists and to permit fabrication of various ornamental and decorative products by hand and without the need for expensive and complex forming tools or dies.
It will be apparent from the following description, which should be read together with the accompanying drawings, that there are other advantages of the present invention as is apparent from the disclosed preferred embodiments of the various forms of this invention.